Telecommunications services in general may be controlled to some degree by the sender or by the receiver. The message content, the message medium and the timing of transmission are normally under the control of the sender. However, the recipient may for example influence the delivery of a communication by activating a message storage facility or by switching his phone off. Generally facilities available to a recipient for control of incoming communications are quite limited.
Text messaging services are prevalent in modern telecommunications networks and are enjoying continued growth. The networks are handling increasingly large volumes of message traffic, and so many networks are exploiting new technologies to improve the efficiency of message transmission.
GSM networks are specified in the relevant standards, and these define that the GSM short messaging services (SMS) are implemented by a store and forward device known as a Short Message Service Centre (SMSC). This technique is analogous to recorded voicemail, and was most beneficial in the early days of GSM, when handsets were less portable that they are today, battery life was poor and radio coverage was limited. At that time only a small proportion of text messages were deliverable at the first attempt, and so a store and forward device was appropriate.
Today the converse is true, and many networks report that 80% or more of messages are deliverable on the first attempt. Networks are therefore turning to alternative techniques for message handling to avoid the delays and cost involved in sending all messages via a storage medium. Typically, improved efficiency is gained by the use of SMS Routers in the network that allow each message to be selectively delivered by an appropriate method according to the characteristics of the message. Person-to-person traffic may be directly delivered to the recipient, and only if the recipient is unreachable is the message then passed on to a store-and-forward device instead. SMS Routers may implement throttling, load balancing, address translation and other facilities within the network to improve the efficiency or scope of services offered to subscribers.
Many facilities are available to the sender of SMS to allow him to choose the method of delivery. Some networks have partially implemented the format translations specified by the GSM standards, allowing for example a sender to indicate that a message is to delivered in fax format, and to send it to a fixed-line or mobile fax number. Also some networks support various text prefixes within the body of the message to control such features as delayed or timed delivery. Text to speech systems have been implemented by a number of operators, allowing messages to be read out during a voice call, but the feature is only selectable by the sender.
We have appreciated that it would be desirable to enable the receiver to have more control over the mode of delivery of text messages. We consider that it may be desirable for the receiver to be able to control, for example, the timing or method of delivery, or the medium by which delivery is made.
For the recipient, SMS currently offers few options. For example, although specified by the GSM standards, there is no divert facility available for text, and no translation to a different medium is available to be specified by the recipient.
Prior art for recipient control in telephone systems includes                PBX facilities for diversion, forwarding, do not disturb etc.        Voice mail that can be selectively switched on or off        Dual or multiple SIM card support in some networks which gives some limited control of to which terminal a message is delivered.        
The present invention is aimed at providing a means by which network operators may offer a greatly enhanced level of control to text message recipients.